Chromium complex disazo dyestuffs



United CHROMIUM cos trim orsAzo nYEsrUrFs Rolf lfiitter, Dusseldorf,Germany, assignor toFarbenfabriken Bayer Aktiengesellschaft, Leverkusen,Germany, a corporation of Germany No Drawing. Application November 13,1952, Serial :No. 320,340

Claims priority, applicationGermany November 15, 19 51 8 Claims. (Cl.260-143) The present invention relates to new disazo dyestufis and theirchromium complex compounds and to processes of making thesame; moreparticularly it relates to disazo dyestuffs of the general formula:

wherein A has the same meaning as stated above and benzene nucleus Bbears in one of the o-positions with respect to the NHz-group a hydroxygroup, with hydroxynaphtha'lenes, l-aryl-S-pyrazolones,acetoacetarylamides or substitution products of these couplingcomponents which are, however, free from sulfonic and carboxylic acidgroups. The aminomonoazo dyestuffs used as starting diazo components arein general known compounds obtained e. g. by coupling a diazotized diazocomponent of the benzene or naphthalene series containing a sulfonicacid group, with a 2-acylamino-1-hydroxybenzene and converting theacylamino group in the monoazo dyestuff thus obtained into an aminogroup by saponification. Suitable diazo components of the benzene andnaphthalene series used here are e. g. l-aminobenzene-l-sulfonic acid,1-aminobenzene-3-sulfonic acid, 1-aminobenzene-2- sulfonic acid or theirsubstitutionproducts such as lamino-4-methylbenzene-Z-sulfonic acid,l-amino-4-methylbenzene-ii sulfonic acid, 1-amino-4-chlorobenzene-Z-sulfonic acid, 1-aminonaphthalene-4-sulfonic acid, 1-aminonaphthalene-S-sulfonic acid, l-aminonaphthalene- 6-sulfonic acid,1-aminonaphthalene-7-sulfonic acid, mixtures of the 1,6- and the1,7-acid, Z-aminonaphthalene-G- ,sulfonic acid,Z-aminonaphthalene-S-sulionic acid.

The disazo dyestufis described above can be converted into thecorresponding chromium compounds by a treatment with chromium yieldingagents; this treatment can be carried out either with the dyestuiis assuch or with the dyestuffs on the fibre and in the latter case either bythe one-bath chrome process or by the after-chroming process.

The new dyestuifsconverted into the chromium comatet Patented Aug. 20,1957 plex compounds either in. substance or on the fibredye animalfibres or polyamide fibres brown to olive shades of good fastness tolight and wet treatment. The

chromium containing .dyestufis prepared. in substance ,show. thefur'theradvantage of dyeing well. animal fibres from neutral toweakly aciddyeing baths.

The following examples illustrate the present invention without,however, limiting it thereto:

Example 1 17.3 grams of 1-aminobenzene-4-sulfonic acid are diazotized inthe usual manner and added at O-5 C. to a solution prepared from l5.lgrams of Z-acetylamino-lhydroxybenzene, 10 cc.,of a percent caustic sodasolution and 25 grams of sodium carbonate in 100 cc. .of water. Afterstirring the mixture for half an hour,

.of its volume of a 30.percent caustic soda solution; is

. C with good stirring. After complete diazotization the solution iscoupled with an alkaline (caustic soda) solution of 14.4.gramsofZ-hydroxynaphthalene. The disazo dyestutf is separated at a pH-value of10 by adding sodiumchloride and filtered; it corresponds in the freestate to. the formula:

. dyeings show good fastness to wet processing and to light.

By the monochrome method dyeings with similar fastness properties areobtained.

Example 2 47 grams of the o,o'.-dihydroxydisazo dyestuff described inExample 1 are dissolved in water with addition of caustic sodasolutiomat 20 C. the solution is rendered wveakly acid with acetic acidand a solution of 30 grams of chromium fiuorid (containing crystalwater) is added. The mixture is then refluxed for several hours until atest sample shows nomore dyestufi free of chromium.

.After adding sodium chloride the. chromium-containing dyestufi can bewell filtered.

The conversion .into a chromium complex compound can also be carried outin a shorter time; this is done in the following way:

290 grams of a basic chromium sulfate solution corre sponding to 76grams of C1'203 are mixed with 5 litres of water and, after adding 276grams of salicylic acid, heated to the boil. The, mixture is renderedweakly alkaline by slowly adding a 30 percent caustic soda solution andthe clear solution is filled up to 7 litres. 47 grams of the disazodyestuit prepared according to Example 1 are dissolved in 1 litre of hotwater with addition of caustic soda solution to which 500 cc. of theabove-described chrome-salicylic acid solution are added. The mixture isthen refluxed at the boil until the original dyestuff can no longer bedetected. The chromium-containing dyestufi thus obtained is separated atneutral reaction by adding sodium chloride and dried. After grinding thedyestuif is obtained as a black powder. Animal fibres and also polyamidefibres can be dyed therewith from an acid to neutral bath in black-brownshades showing good fastness to wet processing and to light.

Example 3 17.3 grams of l-aminobenzene-2-sulfonic acid are diazotizedand coupled with 15.1 grams of 2-acetylamino- 1-hydroxybenzene to themonoazo dyestufi according to Example 1. The dyestutf is separated byadding sodium chloride, filtered and saponified with dilute hydrochloricacid at 80 C. After cooling the hydroxyaminomonoazo dyestuif is isolatedand dissolved in water with addition of caustic soda solution. 7 gramsof sodium nitrite are added to the solution which is then dropped intodiluted hydrochloric acid at 5-10 C. with stirring. Finally thediazotization mixture is' stirred for a further half hour and then addedto an alkaline (caustic soda) solution of 14.4 grams of2-hydroxynaphthalene. After adding sodium chloride the disazo dyestuifobtained is filtered oif; it corresponds in the free state to theformula:

It dyes wool red shades. By converting the dyestulf on the fibre intothe chromium complex compound, a black-brown shade is obtained which isfast to wet processing and to light. By treating the dyestulf insubstance with chromium yielding agents according to Example 2 afterdrying a black powder is obtained which dyes wool or polyamide fibresblack-brown shades of good fastness properties.

If instead of l-aminobenzene-Z-sulfonic acid the corresponding diazocomponents containing in 4-position a CHsor Cl-substituent are used,dyestuffs of similar fastness properties and shades are obtained whichare, however, better suited for the monochrome method than theunsubstituted ones.

Example 4 The diazo compound of 22.3 grams ofl-aminonaphthalene-4-sulfonic acid prepared in the usual manner is addedto a solution of 15.1 grams of Z-acetylamino-lhydroxybenzene, 10 cc. ofa 30 percent caustic soda solution, 25 grams of sodium carbonate and 100cc. of water. After stirring half an hour the solution is heated to 90C. and of its volume of a 30 percent caustic soda solution is addedthereto. The temperature is maintained for one hour at 90-100 C.; thesolution is then rendered weakly acid, and the precipitation of theaminohydroxymonoazo dyestulf is completed with sodium chloride. Thedyestuff is filtered off at 70 C., dissolved in water with addingcaustic soda solution and quickly poured into diluted hydrochloric acidat 5 C. with stirring. While this temperature is maintained a solutionof sodium nitrite is slowly added until the detection of nitrous acidremains positive. The diazotization mixture is added to a sodiumhydroxide alkaline solution of 14.4 grams of Z-hydroxynaphthalene. Afterstirring several hours the dyestufi is filtered off without furtheradding sodium chloride and then washed with a 5 percent sodium chloridesolution. The dyestuff thus obtained corresponds in the free state tothe formula:

and yields on animal fibres and polyamide fibres red 4 shades which,when treated with chromium yielding agents, change to black-brown shadesof good fastness properties.

52 grams of the dyestuif described in this example are dissolved in 800cc. of hot water with 10 cc. of caustic soda solution. 450 cc. of thechrome-salicylic acid solution prepared according to Example 2 are addedthereto. The mixture is heated with stirring until the originaldyestufif can no longer be detected. Now sodium chloride is added. It isonly after further heating that the chromium-containiug dyestuffseparates in a form which can be well filtered. It is filtered off anddried. The chromium-containing dyestufi is obtained as a black powderand dyes animal fibres and polyamide fibres from an acid or neutral bathin black-brown shades showing good fastness to wet processing and tolight.

When using in this example instead of Z-hydroxynaphthalene 17.7 grams ofacetoacetanilide or 21.5 grams of1-(3'-nitrophenyl)-3-methyl-5-pyrazolone, disazo dyestuffs are obtainedwhich, when converted into their chromium complex compounds either onthe fibre or in substance, dye animal fibres and polyamide fibres strongreddish brown shades which show good fastness to wet processing and tolight.

When replacing in this example the 2-hydroxynaphtbalene by1-acety1amino-7-hydroxynaphthalene, the chromium complex compoundprepared on the fibres or in substance yields on animal fibres andpolyamide fibres an olive-green which shows good fastness to wetprocessing and to light.

If at first diazo component 1-aminonaphthalene-5- sulfonic acid isemployed in the above described combinations instead of1-aminonaphthalene-4-sulfonic acid, dyestulfs of similar properties areobtained.

Example 5 22.3 grams of 1-aminonaphthalene-4-sulfonic acid arediazotized in the usual manner and added to a solution of 16.5 grams of2-acetylamino-4-methyl-l-hydroxybenzene, 10 cc. of a 30 percent causticsoda solution and 25 grams of sodium carbonate in 150 cc. of water. The

monoazo dyestulf obtained is separated by adding sodium chloride,filtered olf, dissolved in cc. of hot 5 percent caustic soda solutionand heated for one hour to C. Then the solution is rendered weakly acidand the precipitation is completed by adding sodium chloride. Theaminohydroxymonoazo dyestuif thus obtained is dissolved in water withadding caustic soda solution; thereafter 7 grams of sodium nitrite areadded and the mixture is dropped into diluted hydrochloric acid. Afterthe diazotization is finished the mixture is added to a solution of 14.4grams of Z-hydroxynaphthalene, 15 cc. of caustic soda solution and 25grams of sodium carbonate in cc. of water. After stirring for 4 hoursthe disazo dyestufi thus formed is filtered off without previouslyadding sodium chloride and dried. It corresponds in the free state tothe formula:

and dyes animal fibres and polyamide fibres red shades. By anafter-treatment with chromium yielding agents in the usual manner andalso by the monochrome method, bluish grey dyeings are obtained whichshow good fastness to wet processing and to light.

53.2 grams of the disazo dyestufi described in this example aredissolved in water with adding caustic soda solution and 700 cc. of thechrome-salicylic acid solution mentioned in Example 2 are added. Afterheating for several hours the original dyestuif can no longer bedetected. The chromium-containing dyestutf is separated from thesolution by adding sodium chloride and filtered. It dyes animal fibresand polyamide fibres from an acid or neutral bath grey shades which showgood fastness to wet processing and to light.

Example 6 17.3 grams of 1-aminobenzene-4-sulfonic acid and 15.1 grams ofZ-acetylamino-l-hydroxybenzene are coupled to the monoazo dyestufiaccording to Example 1, saponified and further diazotized. Thediazotization mixture obtained is added to a solution prepared from 21.7grams of carbomethoxy-1-amino-7-hydroxynaphthalene, 70 cc. of pyridine,150 cc. of water, 9 cc. of a 30 percent caustic soda solution and 30grams of sodium carbonate. After stirring for 5 minutes further 20 cc.of caustic soda solution are added. The dyestuff separates soon and isisolated. It corresponds in the free state to the formula:

CHzO.CO.NH

After drying it represents a dark powder which dyes wool from an acidbath red shades; by an after-treatment with chromium yielding agents theshade changes to olive. The dyeing shows good fastness to wet processingand to light.

The dyestuff can be converted into its chromium complex compoundaccording to the process of Example 5. After drying it represents abrown-black powder which dyes wool from a weakly acid bath olive shadesof good fastness properties.

I claim:

1. A chromium complex of a disazo dyestufi of the formula AN=N--Xwherein AN=N stands for the radical of a diazo component containing asulfonic acid group selected from the group consisting of the benzeneand naphthalene series, C stands for a coupling component selected fromthe group consisting of 2-hydroxynaphthalenes, l-aryl-S- pyrazolones andacetoacetarylamides free from sulfonic and carboxylic acid groups, oneof the radicals X attached to benzene nuculus B represents a hydroxygroup and the other hydrogen.

2. A chromium complex of a disazo dyestuif of the wherein AN=N standsfor the radical of a diazo component containing a sulfonic acid groupselected from the group consisting of the benzene and naphthaleneseries, C stands for a 2-hydroxynaphthalene free from sulfonic andcarboxylic acid groups, one of the radicals X attached to the benzenenuculus B represents a hydroxy group and the other hydrogen.

3. A chromium complex of a disazo dyestufl of the formula i'I=N Cwherein AN=N- stands for the radical of a diazo component containing asulfonic acid group selected from the group consisting of the benzeneand naphthalene series, C stands for a Z-hydroxynaphthalene free fromsulfonic and carboxylic acid groups.

4. A chromium complex of a disazo dyestufi of the formula formula:

7. A chromium complex of a disazo dyestuflf of the formula:

HOaS =NQ-OH HO 8. A chromium complex of a disazo dyestufi of theformula:

SOsH N=N CH5.CO.NH

References Cited in the file of this patent UNITED STATES PATENTSKirchhoff Ian. 2, 1894 Lange Apr. 4, 1939 Neier et a1. Feb. 21, 1956Neier et a1. J an. 29, 1957

1. A CHROMIUM COMPLEX OF A DISAZO DYESTUFF OF THE FORMULA: